Must Restart Computer

Help,
I recently tried to put a PCI (Similar to Airport) wireless card in my G4 with no luck.
I took out the PCI card and restarted my G4 and now I constantly get the dim grey/black
screen that says to "Resart Your Computer". I can reboot off of my backup drive just fine.
But the Original HD does not mount. The original HD will show up in OS9.2 but not in OSX3.9
Can someone help me get my Original HD back in OSX.3.9
Thank you

Try re-setting the motherboard - it's a little red dot near the PCI slots - full details can be found on Apple.com by searching under Motherboard reset (I use the Applecare section of Sherlock to find all this kind of stuff)